1. Field of the Invention
The present invention relates to a method of transmitting data sequence which is suitable for use in, for example, an audio PCM tape recorder and, more particularly, to a method for encoding error-correction-code which is applied to record, e.g., an audio PCM signal on a magnetic tape by a rotary head.
2. Description of the Prior Art
There is known a method for performing the error detection or encoding error correction codes in the longitudinal and lateral directions of digital information data arranged like a matrix, respectively. As one method in case of transmitting these codes for every column and decoding them on the reception side, there is considered a method whereby the error detection is performed by a first error detection code for each column, a pointer as a result of this is produced, and the data and pointer of each column are stored in a memory, then the error correction is performed for every row by a second error correction code with reference to this pointer.
On one hand, the number of quantization bits of the audio PCM signal may vary in dependence upon the objects in use of the audio PCM signal recording/reproducing apparatus, or the like. Namely, to record and reproduce the audio signal with high quality, the sampling frequency f.sub.s is set into 48 kHz and the number of quantization bits is set into sixteen bits. To record and reproduce the voice signal at a conference and the like, the sampling frequency f.sub.s is set into 32 kHz and the number of non-linear quantization bits is set into twelve bits. When the sampling frequency is low, this enables the recording and reproduction to be performed at a half speed of the standard running speed of the magnetic tape (i.e., of the standard rotational speed of the rotary head), so that it is effective to reduce an amount of magnetic tape as the recording medium to be consumed.
It is desirable that the encoder and decoder for performing the error detection and error correction as mentioned above are constituted by a common hardware regarding a plurality of number of quantization bits and that they have the similar error correcting ability even in any cases.